hi can anyone help once again, switched the car on this afternoon was driving and heard this strange noise like if i metal was rubbing somewhere, i thought something might of got stuck on the tyres, the more faster i went the more the noise, so pulled over checked the tyres but than realised that its from the engine, it was actullay coming from the belts i think, so reved the engine a few times, switched it off on again and the sounds gone, can anyone think what it can be, i was thinking that it may be some dirt or stone on the belt??